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If you have a wood pellet boiler then one of the key considerations is understanding whether it will leave you better off.

1 – if you have a recent EPC or Green Deal Assessment there will be two figures on the last page (p 4 of 4) that show you how much space heating, and how much hot water you require in kWhrs. For instance this could be 33,000 hrs and 2500 hours.

2 – If you require to update loft insulation or cavity wall insulation there will also be an estimate on how much this will save you in heating hours.

You now have the information to use the governments Domestic RHI calculator. The advantage of this is that they do keep all the tariffs up to date, so you will know what you will get, providing you install before a certain date.

Once you have figure for what you will get there are key considerations that you can estimate yourself:

What size boiler do I need?

The first thing to do is to roughly calculate what size boiler you need. For instance if your home requires 32000 kWhrs a year of heat then you need to estimate how many hours the boiler will be used for over 1 year.

Estimate 1 – The RHI commercial figure is 1314 hours a year

Estimate 2 – The Energy Savings Trust figure is 1100 hours per year

In reality the figure can vary according to house type – if you have a lot of heat loss e.g. stone walls, then you may need more boiler hours because you are losing lots of heat. If you have a very well insulated home then the home will conserve heat. This is important when it is very cold and determines whether your boiler can keep up with your home’s need.

So – 32000 hours = 24kW boiler using the first estimate or 29kW using the second

If you have secondary heating e.g. a log stove then you may feel that you could use a smaller boiler. If you have poor insulation and no extra heating then you may want a larger one.

If we are invited to do a survey then we have to calculate the size of the boiler, and we do not rely on the EPC figure. However this estimate gives you a starting point.

Once you have got a boiler size it is possible to get a ball park figure for a boiler room installation e.g. no changes to the central heating system, just the replacement cost of the boiler subject to survey.

If you would like us to give you a figure, then please contact us. We do find that our prices are quite reasonable.

Key points from the Guardian article are that a DECC study of installed biomass systems found that the average efficiency of the boilers was 66.5%, that the surveyed systems can only reach 76% efficiency, and that this is lower than the needed 85% efficiency to contribute to carbon targets. Yet the original research also states “In other words, the estimated central performance standards of 81.5% to 72% (and 76.75% on average) would only be slightly exceeded if the boiler were gas, oil or coal fired.”

Whilst the article was clearly pushing heat pumps, a rival renewable technology, there seems to be confusion in the text.

To qualify for the Renewable Heat Incentive biomass boilers have to conform to a European Standard EN303-5. In addition to this the boilers have to be tested to emit limited emissions.

The 85% efficiency relates to the EN303-5 standard and the class of boiler that can be used for an RHI Scheme. This is calculated in lab conditions from the burning of a specific fuel. This is not the overall efficiency of the heating system.

Over the last 2 years there are a number of variables that may have influenced the study.

Issue 1 – Heat Meters

Heat meters are used to measure effective heat that is used by the RHI biomass system. What is recorded on the heat meter is what is paid to the owner of the system. In the majority of cases the heat meters are placed on the entrance to the heated spaces. Thus they only measure what is being used, and not what is being wasted. In addition there have been some issues with the installation and accuracy of the meters, where the accuracy can vary by up to 30%. There are currently free courses to help remedy this.

Issue 2 – Fuel

When the RHI first came into being the boilers could be tested on a very efficient fuel, but in reality the boilers were using a similar fuel that was much less efficient.

For instance you can buy wood briquettes that can have a low moisture content e.g. 8%. These will burn very efficiently, in excess of 90% in the right conditions. However if you use logs that are not properly seasoned then the moisture content will be much higher e.g. 30%, and the efficiency of the burning process may be as low as 65%.

This issue has been addressed in part by a tightening of the specifications. However there are boilers installed that are burning poor quality fuel as it is cheaper than specified fuel. This is more prevalent with landowners or farmers. Today all newly installed boilers should only be burning specified fuel and the boilers should be able to burn with an efficiency of above 85%. Owners of the installation have to keep records of the fuel they have purchased.

Wood Pellets all have to be ENplus. Regular samples of pellets are taken and they are measured for moisture, dust (fines), hardness, and burn quality. There have been some issues with dust in particular. The pellets can degrade in transit and when loaded into a hopper. There are examples where the dust content can rise above 10 or 15%. Clearly this makes the efficiency of fuel to heat produced less efficient. Again these issues are often dealt with by an experienced installer, or many of the good distributors will offer replacement pellets if they have been wrongly handled. There are very few issues with bagged ENplus pellets.

The majority of the boilers in the study seemed to be using woodchip at 199kW. In the case studies provided the fuel used was often wood chips with a moisture value of 30 or 31 percent. Wood Chips are significantly cheaper than wood pellets, but burn less efficiencty, and therefore will have a poorer efficiency. For instance if the burn efficiency of 31% moist pellets is 80% then the heat transfer to water will be below 80%. This will largely explain the number of responses that seemed to be 70% + and fairly well installed.

Issue 3 – sizing of boilers

With Solar PV everyone who purchased wanted as much as possible. This produces more electricity, which is a good thing! For biomass the owner of a system gets paid the highest tariff up to 199kW. So if you are buying a biomass system for investment purposes then it seems that choosing 199kW will earn you more money.

The difficulty with this is that this causes 2 problems. a) The boiler is not run at its most efficient output. This is true, for instance, for many combination condensing boilers that have been sized for hot water production and not heating need. The boiler never reaches its optimum output and is less efficient as a consequence. b) The heat is not really needed. Here the owner is more interested in the tariff rather than the efficient distribution of the heat. The heat is then lost.

Issue 4 – UK weather and system management

UK weather presents a number of issues. Firstly we do have mild winters and cold winters. This can relate to the sizing issue. When you size a boiler you examine possible temperatures that you want the boiler to be able to cope with. For many this may be -3 degrees. In reality we may experience the majority of the winter with temperatures of between 6-12 degrees.

The other issue with UK weather is that it is intermittent. We generally do not need the heating on all day every day. Therefore you have to consider carefully when the heating needs to be turned on. If the following month is then warm you will wast the heat that is already in your system. For instance if you have buffer tanks and have spent time heating them up, only not to use the heat, then this heat could be lost and not used.

Issue 6 – General heating system efficiency

What is not clear from the Guardian article is how the efficiency is measured. The original article is far clearer and looks at the whole system efficiency rather than implying that the efficiency is all down to the boiler.

Before the heat gets to the heat meter there may be pipework (lagged), district heating pipe work, buffer tanks, and the transfer of the heat from the burn chamber within the boiler to hot water.

Examining the transfer from heat to water, there is a UK database that is slowly expanding that shows that heat to water efficiency (typically 80-86%) from biomass boilers rather than the burnt efficiency of the burning process that is often above 90%.

Due to the nature of the study being more about 199kW boilers for predominantly large retail systems with possibly wood chip boilers, it does not cover smaller systems that do not have district heating, or many pellet boilers.

If you are in doubt over what your system efficiency is or even means, then please get in touch with us.

In the UK the introduction of the Renewable Heat Incentive has meant that the definition of biomass fuel has become more difficult to understand. The main driver for this are the emissions that the boilers have in addition to CO2 being of acceptable levels.

These limits are 30 grams per gigajoule (g/GJ) net heat input for particulate matter and 150g/GJ for NOx.

Each boiler range has to be tested with the fuel that is going to be used within it. Each fuel has a definition.

Wood Pellets

Pellets are the most straightforward for a homeowner as there is an ENPlus quality standard market on bagged pellets or on the website of the pellet producer.

All accredited wood pellet boilers have been tested to a European Standard EN303-5, met the standards of the UK Microgeneration Certification Scheme, and have a valid emissions certificate. Key to this is that the boilers were tested on ENplus pellets. So these are the only pellets that you can buy and use. To claim your RHI you will have to keep records and be able to show that you are burning ENplus pellets.

Wood Pellet Boiler Product Example

Pelleburn 15kW wood pellet boiler will burn ENplus pellets only. When it does this it has been tested to show 9g/GJ for Particulate Matter and 81g/MJ for Nox. You can find a copy of the emissions certificate here. http://rhieclist.org.uk/wp-content/uploads/2014/04/NES_PLB_RHI.pdf

Wood logs

Logs are measured by moisture and by whether they are “virgin” or used. This potentially creates 4 categories.

Virgin timber – Very dry or kiln dried logs or logs with less than 25% moisture

Wood burns much better and cleaner when the wood is dry. The testing process and regulations ensures that if you buy and use a log boiler you take care of what you put in it. For instance the following are attractive, but not allowable

Newly cut timber in excess of 25% moisture. Fuel that you “find” in woods, or offcuts from timber merchants, or branches from a tree surgeon. This fuel will not burn well. You do not get the heat but your neighbours get the smoke.

MDF, Chip board or painted wood may burn, but it gives off lots of fumes. Unless there are very specific cleaning processes within the boiler to deal with paints and glues then the fumes produced will be toxic. This category of fuel (B2) cannot be burnt in the majority of boilers, and certainly no domestic or small boilers.

Logs can transformed into wood chip and sawdust and is subject to the same categories as above. Wood chip is generally quite bulky, so produced in local areas rather than pellets at one or two places. It varies in quality and next year (2015) suppliers will need to state that their fuel meets both a moisture standard and has no contaminants. We are excited about our new boiler The CB 160 which will shortly be released into the UK market.

Sawdust does not burn well and can cause back burning (fire can go back through the fuel delivery mechanism) boilers will specifically state whether they can burn sawdust or not. For instance the Catfire range of chip boilers can burn sawdust and has a mechanism to prevent backburning of sawdust.

Sawdust or shavings can also be made into briquettes easily (and pellets, but not so easily) that can burn very well and burn in most boilers.

As part of understanding the moisture content of the wood you would need to have an adequate storage and inspection process. For instance with pellets you need to check that there is not too much sawdust. For wood you will need to store so that the wood can mature. For chip you will need to keep it for a short period to ensure that it does not compost. Other than pellets, you will need to get a moisture meter to make sure that your wood is less than 25%.

Biomass boilers burn “biomass”. In theory this could be burning anything that has been recently living, probably plant matter, in a boiler.

We often get questions like:

“can your boiler burn logs and pellets at the same time?”

“Can we burn any sort of wood in your boiler?”

“is it possible to use Miscanthus in your boiler?”

Oh, and:

“why do i get klinker / Clinker in my pellet boiler”

This article is intended to help you in your path towards choosing a biomass fuel that works for your situation and matching it to the sort of boiler that you may want to use.

We are happy to answer questions. Please contact us using the form on the side of the page.

Part 1 – different burning materials

It is possible to burn almost anything. However if you have ever tried to burn plastic then you know that the fumes that are given off are toxic and the gas leaves a residue that is difficult to shift. Therefore when choosing burning materials you can only use materials that will burn cleanly without leaving a difficult to clean residue.

As well as burning cleanly you also do not want to have too much ash left over to clean out of the boiler. Therefore some possible burning materials that leave behind clinker or partially burnt materials and again give you extra work to do.

Different burning materials burn best in different conditions. It is therefore likely that you need different amounts of air to burn each material. Your boiler has been tested for specific burning materials and probably commissioned for one. Unless there are specific claims by the boiler, then it is unlikely that it can burn more than one material at a time.

If you are interested in grants then the biomass materials that you consider need to be approved i.e. burning them is more beneficial to the environment than burning fossil fuels.

This means that the boilers have to be engineered to only burn “biomass” rather than a fossil fuel. Biomass in the real world is any living matter, but in the world of the RHI it means an accredited boiler where the boiler has been tested to work efficiently with a given fuel. Biomass in the domestic and small business market therefore means:

Logs – seasoned to at least 20% moisture for good burning and possibly less depending on the boiler

Pellets – dried to 10-12% moisture and made from virgin sawdust

Wood Chip – dried to 15% moisture

There are other fuels that are discussed, but less readily available e.g. cherry stones, pine kernels, olive stones etc which can burn in a small number of boilers

If you have a wood or a supply of logs then an important consideration is the moisture content of the logs. Using a moisture meter you would need to test not just the outside of the log, but the internal part of the log as well (you can split the log). The consequences of using damp materials can be condensation that causes tar and furs up the inside of your boiler. You get a less effective burn and you need to clean your boiler more often.

Part 2 Examples of different biomass boilers

Log Burning Boilers

The picture above shows the most simple log boiler (WBS). It has no electronic controls and so works with minimal electricity (just a pump). This will work with logs that are 20% moisture or less. Once the logs are loaded then the boiler will burn for about 3 to 3.5 hours and heat a large tank of water that is used as a store to heat a home. During the coldest parts of winter this would be done twice per day. The boiler is very cost effective with prices starting at around £1000.

Most log burners can only burn logs, however the WBS has been fitted with a flange and designed to burn effectively with pellets. This combination has been tested and is MCS accredited below 45kW and is applicable for the non domestic Renewable Heat Incentive up to 110 kW. We should stress that you can only burn either logs or pellets in a single moment. To change from one to the other is a simple process, but it has to be done.

The picture above is a more complex log burner WBS active. It is a few hundred pounds more than the WBS and has the addition of a controller and a fan. The advantage that this brings is that the boiler controller can respond to the heat of the water that it is producing and turn the fan off. This reduces the flame of the boiler and the water will stay at the given temperature for a period of time. The benefit this gives is that if your water store is already hot then your log load will last for longer perhaps 6 hours before it is burnt out.

This model also has the option of a pellet burner insert and is also accredited for the Renewable Heat Incentive.

The above image is a gasification boiler, Pyroburn Alpha. This burns with very dry logs. When logs burn they give off a gas called Syngas and this can be burnt and produce more heat given the opportunity. This boiler has a second burning chamber, a variable fan and a more advanced controller. The overall result is an increase in the efficiency of the burn of wood. It is a little more expensive but prices still start at around £2000 and comes in 3 sizes 18, 25 and 40kW. It cannot burn anything other than dry wood.

The Pyroburn Lambda is a more advanced model again. This has an additional lambda sensor that automatically adjusts the burning. This makes fitting easier and ensures optimal efficiency of burn. This is around £1000 more expensive.

Log boilers can vary in price and what they can do – the more controls you put in the more efficiency gains are possible, however this relies entirely on the quality and moisture content of the wood that you put in. It may be that if you are not prepared to ensure the lowest moisture content of your wood due to the extra expense it will incur then you are better off with a simpler model. If on the other hand efficiency of burning is your priority then the Pyroburn Lambda could be an excellent choice with up to 93% efficiency recorded in the field in working models.

Multifuel Biomass Boilers

Boilers such as the Combi Burn 35kW have 2 burning chambers and can swap easily from one fuel to another.

This means that you can burn wood and then revert to an automated fuel such as wood chips or wood pellets automatically. The boiler is a little larger than the above boilers, but is considerably more flexible. It is a more involved design, and the boiler costs more to make.

Wood pellet boilers

Wood pellet boilers come in lots of shapes and sizes. Most installations are wood pellets. The wood pellet is automated and therefore easier to use. Log boilers can be cheaper but require more space and suit businesses and organisations that can feed a boiler. This could be a farmer who is near to the boiler most days. For those that have to travel to work you want your boiler to provide heat automatically and this may be when you are not there.

Wood pellet boilers use a hopper to deliver pellets to a burning chamber. On domestic models boilers such as the Musa by MCZ or the LP14 by Extraflame have an internal hopper that you would need to fill by hand several times a week during winter. You would probably buy your pellets in bags.

The above diagram shows how the pellets are fed from the hopper (behind) into the burner unit on the LP14. It is a very similar process with all Italian made boilers.

The Pell burner unit mentioned earlier can be fitted onto a WBS boiler or comes as part of a Pelleburn boiler.

Here the pellets are fed from a 500l hopper into the top of the burner and then an internal screw pushes the pellets into the end of the burner where air is applied and an efficient flame results.

The pelleburn can burn up to 94% efficient. This is due to the technology used towards dedicating the burning purely on pellets.

If you have a larger system or do not want to buy bags of pellets, you can get a lorry to blow the pellets into a pellet store. The advantage of this is that you have the extra cost of the pellet store, however you may be able to get a discount on the buying price of the pellets.

Blowing pellets into a pellet store can be very effective for the home owner as they can leave the pellet system working. We find that there is an even split between those people who are quite happy loading their own pellets and those that want to have a pellet store.

If you want a pellet store then you need to consider how to feed the pellets from the store to the boiler. If you can locate the store near to the boiler then you can use another auger to feed in the pellets. Augers are reasonably cost effective and start at close to £1000 for a 3 or 4 meter auger.

If you need to locate your store further away from the pellet boiler then you will have to use a vacuum system. This involves more technology and more pipe. It will push up the cost of your installation by up to £2-5000 depending on the options you go for.

The storage units themselves are designed for either inside or outside. Inside units are a little cheaper, and outside units do not need a special store.

The above unit is an example of an internal storage system supplied by Geoplast. A larger system could store up to 9 tonnes including an auger could cost in the region of £4-5000.

The alternative is to build your own store. This is very possible, but often a similar cost.

Part 3 Buying biomass fuel

Wood, whether it is wood pellets, wood chip or logs can be a complex subject and off putting to a potential purchaser. The industry recommends only good fuel because you will either get boiler problems or you will need to clean your boiler more frequently. Part of the problem is that a beautifully packed carton of logs from a petrol station can be very expensive.

Look for good wood pellets

Wood pellets need to be approved. You can look for signs such as

This will insure that the pellets are of top quality. Pellets are made in quantity in the UK and 2 of the largest manufacturers are Brites and Verdo Renewables. There are many other manufacturers setting up and in your local area there will be a distributor that can deliver in bags or via a vehicle.

Pellet prices are about 20-30% cheaper than oil or LPG prices and prices do fluctuate, but not by as much as oil or LPG.

A1 pellets will burn well, and you also will want to know that the sawdust that created the wood pellets came from a sustainable sourced forest. An FSC scheme is put in place to ensure that the wood that is cut down is replaced.

If you examine closer you will find that the whole tree is often being used for timber through a saw mill. The sawdust is simply a byproduct.

Use a local distributor and work with them

Transporting wood pellets is expensive. Getting 1 tonne to your door at your convenience can be very expensive. Distributors work hard to deliver pellets in a system and therefore letting them know in advance what your needs are can bring your costs down.

Do shop around. There are often deals to be done. For instance you may get your 10th tonne free if you are a bulk user.

Logs need some care

Logs can also come from sustainably managed sources, however the difficulty is the moisture of the logs. If you buy them wet or dry or by tonne or volume, you want to know that the wood will work well in your boiler. For instance dry willow will burn very quickly and it is not very energy dense. Ash contains a lot more energy.

You will find that a local supplier is best as logs are heavy and cost a lot to transport.

If you are using your own logs then you will also need to consider how you are going to dry them.

Even dry logs need good storage. If left in the open seasoned timber will still absorb moisture.

When you first get a log boiler then there will be a learning process as you adjust both the cost of the wood that you buy with how well it burns.

Wood Chips also need care

Wood chip boilers generally need some space. Wood chips can also compost and need some management. Wood chips are also expensive to transport in small volumes. In our experience wood chip boilers can only work at a lower level e.g. 30-35kw if you have a source on your doorstep.

At larger sizes e.g. 100kW + then wood chips can be much cheaper than pellets and also carry the benefit of the automation of pellets in small quanitities. So for commercial systems wood chips can be very popular. Tree surgeons, joiners, or any tradesman that works with wood chip may find that a chip boiler works very well for them.

All of the above information is quite general. We are happy to have a conversation about your specific thoughts. Please contact us using 01225 580 401

They want to create energy from their trash, but their citizens are far too eco friendly to create enough trash.

They produce biomass and biogas from this waste, which is used as energy.

Each swede produces just over half a ton of household waste every year. Thanks to the efficient waste management in sweden, the vast majority of this household waste can be recovered or reused. Only four per cent is landfilled, which has lead to a rather interesting problem and solution.

Rather than simply producing more trash and recycling less, they have begun importing trash from other countries; roughly 800,000 tons annually. And what’s more, they’re getting paid to take it. Norway have started exporting their rubbish to Sweden, and Bulgaria, Romania, and Italy are set to follow suit.

Just over two million tons of household waste is treated from waste to energy in swedish plants every year. These plants incinerate a similar quantity of waste from industries as well. Waste incineration provides heat corresponding to the needs of 810,000 homes, around 20 per cent of all the district-heating produced. It also provides electricity corresponding to the needs of almost 250,000 homes.

Sweden is currently the global leader in recovering the energy in waste.

Energy from Waste. What an excellent idea.

Sweden has had strict standards limiting emissions from waste incineration since the mid-1980s. Most emissions have fallen by between 90 and 99 per cent since then thanks to ongoing technical development and better waste sorting.

Energy from waste is an environmental, financial, safe and stable contribution to the country’s energy supply.

Waste to energy is a recovery method that provides a significant part of Europe’s energy needs. One example of this is that around 50 million tons of waste are processed through incineration every year throughout europe. This corresponds to the heat requirements for the populations of Sweden, Norway, Iceland, Finland, Denmark, Estonia, Latvia and Lithuania.

In Sweden alone, waste incineration generates as much energy from waste to reduce carbon dioxide (Co2) emissions by 2.2 million tons per year. This is as much Co2 as 680,000 petrol-powered cars emit in a year.

Notice that the UK is left off the list of countries above, and that’s because we simply don’t create enough energy from waste yet.

Not in this particular sense at least.

There is another, popular, and domestic way to create energy from waste, and that’s with the use of a wood pellet boiler.

Wood pellets are manufactured from waste wood, such as off cuttings, and saw dust. It is then compressed and dried to create highly combustable and efficient heating fuel.

These pellets are added to a wood pellet boiler. They get transfered from the store to the boiler through the hopper, and are burned, just like you would burn any other fuel, to heat your home. This can be done on a home and industrial scale, and is financially rewarded by the renewable heat incentive.

So while the UK may be behind in creating energy from traditional landfill waste, we’re very much on the forefront when it comes to biomass, in the form of wood pellet boilers.

Wood Pellet boilers first came into production in the USA during the oil crisis of the 1970s. With oil prices being so high, many people were looking for alternatives to burning oil, which increased the popularity of wood pellet boilers.

Although it may have seemed like new technology, it’s actually one of the oldest in the world.

Sure, the boilers are safe, modern, and super efficient, but the idea of burning wood for heat is one of the oldest known to man.

Alas, wood pellet boilers of the 1970’s were before their time, and when prices of oil started to go down, so did their popularity. They weren’t efficient enough yet, and the process was still cumbersome. The price of the pellets seemed expensive in comparison, and in many places, people stopped using wood pellet boilers altogether.

That is, until the late 1990’s.

As oil prices started to rise again, and more and more people became worried for the environment, wood pellet boilers started to gain in popularity.

This time around, wood pellets seemed like a much more viable long term option. Their production was much more common, which brought down the prices, while still leaving the environment unharmed.

You may think that because we’re burning wood to heat our homes, that we’re cutting down trees to do so. This is not the case. Wood pellets are created from waste wood, from sawdust, garden cuttings, and much more. Similar to how no one kills the cow for it’s hide, no one cuts down a tree for it’s wood pellets.

Fast forward 15 years, to present day, and wood pellet boilers have come along in leaps and bounds, all across the world.

Pellets have become increasingly popular in europe, Scandinavia in particular, where they’re mainly used as an alternative to oil-fired heating. They’ve also seen a huge increase of popularity in Austria too, which is leading the market for pellet central heating furnaces, where it is estimated that 2/3 of all new domestic heating furnaces are pellet burners.

Are Wood Pellet Boilers Here to Stay?

Well, lets have a look at some deciding factors of the future of wood pellet boilers.

According to the International Energy Agency, the production of wood pellets in Europe and North America doubled between 2006, and 2010. That’s a total of 14 million tons of wood pellets produced.

In a recent report by the Biomass Energy Resource Center, we find that wood pellet production in America is likely to double again in the next five years. According the the predictions found in that report, the majority of wood pellet production is said to be destined overseas.

Oil prices rose sharply at the end of 2011, and they have remained high. It’s no secret that the world is fast running out of natural heating resources such as gas, oil, and coal. This is forcing their prices up, and forcing consumers to look for alternatives.

As wood pellets can be produced anywhere in the world, their prices aren’t affected by global market prices. The price will likely fluctuate as production costs go up (due to factors such as diesel prices), but wood pellets will remain a viable alternative to gas and oil.

And if you’re still looking to a reason as to why wood pellet boilers are here to stay, there are always the financial implications of the Renewable Heat Incentive, where you can be paid to produce heat from a renewable energy source.

If you would like to know more about wood pellet boilers, please feel free to contact us.

What is a Wood Pellet Boiler?

A Wood Pellet Boiler is an environmentally friendly and cost effective alternative to an oil or gas boiler. They burn wood pellets (made from waste wood) to run the boiler, which provides heating to the rest of the house.

They’re eco friendly, money saving, and are available globally.

How Does a Wood Pellet Boiler Work?

The boiler consists of three main parts: the boiler itself, the hopper (to load the boiler), and the store. The wood pellets are kept in the store, and the hopper automatically adds them to the boiler, to minimise the amount of work that you need to do yourself.

The wood pellet is a fuel, just like gas or oil, only it’s much kinder to the environment, and cheaper to burn too.

Heating your home by burning wood is not exactly a new idea, but the technology we have now is far more advanced and efficient than an open fireplace, and the fuel is much more eco-friendly.

How is a Wood Pellet Boiler Eco Friendly?

The wood pellets are made from wood wastage, so you’re not actually harming the environment by cutting down trees to heat your home.

Wastage is defined as something which can’t be used anywhere else. Wood Pellets are made up from the likes of compacted sawdust, and logging off-cuts.

Something which would have been thrown in a bin, or on a bonfire, is instead used to heat a house. The pellets are made to be incredibly dense, which allows for them to be burned with a very high combustion efficiency.

What are the Advantages to a Wood Pellet Boiler?

The two main advantages involve the environment, and your wallet.

Starting with the environment, by using a wood pellet boiler, you’re reducing the amount of waste produced, while at the same time reducing the amount of gas or oil that’s being used. Wood pellets are a “carbon lean” fuel, producing a fraction of the Carbon emissions of fossil fuels.

Currently, generating heat accounts for 41% of the UK’s total carbon emissions, and it’s partly because only 1% of heat is currently generated from renewable sources. If you can heat your home with a wood pellet boiler, then you’re helping out in a big way.

When you consider the financial aspect (your wallet) of a wood pellet boiler, it’s easy to see where you will start to save money. Because wood pellets are made from a waste product, they’re low cost, especially in comparison to gas and oil.

They can be sourced locally. They’ve not travelled hundreds, if not thousands of miles to reach you. The price of wood is also much less likely to fluctuate as wildly as gas and oil does, as the world market has basically no effect.

And then of course there’s the renewable heat incentive, which will not only pay you to produce renewable energy, but help towards the cost of a wood pellet boiler. More about this in the ‘How Much does a Wood Pellet Boiler Cost?’ section below.

There are more advantages though:

You don’t need to be connected to the grid to produce heat for your home.

It’s available globally.

It can be converted into many different forms of energy.

It’s easy to switch.

Low running costs.

Long Life.

What are the Disadvantages?

There’s really only two real disadvantages to using a wood pellet boiler.

Firstly, the room needed to store the fuel, boiler, and hopper, is bigger than just a traditional boiler. This isn’t so much of a problem if your building is a new build, but if you’re trying to add a wood pellet boiler to an existing property, then you may encounter problems. You also need access to a chimney or a flute.

The other main drawback is that the fuel isn’t free. When you invest in a renewable energy source such as solar or wind, you have the benefit of access to a free energy source though. With a wood pellet boiler, you still need purchase the wood pellets. Of couse, solar and wind are not without their drawbacks. You can’t exactly power your house when there’s no sun or wind.

What do I need to Install a Wood Pellet Boiler?

Many houses can benefit from wood pellet heating, but there area a few things to consider first.

Is the house listed, in a conservation area, or smokeless zone? If so then there may well be limitations on the type of boiler that you can use.

As I mentioned above, you need a wood pellet boiler, a hopper, and a store for your pellets. On top of this, you will need a chimney (or a flue), for the smoke to escape. This will need to be relatively close to the boiler, which is no problem in new builds, but a little more difficult with retrofits. If this isn’t possible, then you will need to install a flue.

You will also need adequate space for the equipment, which can be comfortable stored in a room 2*3 meters wide, and 1.5 meters high. This room would ideally be on connected to an outside wall of the property, because there needs to be an air intake for the fire to burn.

How Much does a Wood Pellet Boiler Cost?

Well, that’s a very general question, but I’ll do my best to break it down for you.

Lets start by looking at the domestic renewable heat incentive, which is a big incentive for anyone looking to switch. For biomass (wood pellets) the proposed tariff range is between 5.2 and 8.7p per kW for a deemed property.

For a typical 3/4 bedroom house requiring 15kW of heat at 5.2p would gain £7174 over a 7 year period. This is approximately similar to a straightforward installation of a pelleburn boiler or similar. At the higher rate of 8.7p the incentive would pay about £12,000 over 7 years.

For wood pellet boilers you can also claim £950.

Pretty good, right?

Now that you can see how much it pays out, lets have a look at how much it can cost.

As the complexity of the system selected increases, the parts and the labour go up in price significantly. However the maintenance levels go down and the efficiency of the system goes up.

Expensive parts include the pellet boiler which ranges in price from £3000 to £17,000 but also:

The flue – this can cost between £750 and £2000.

Accumulation or climate control – between £850 and £2000.

Pellet Store – You can use the integrated hopper that will last you a few days at peak load.

Pump sets and other plumbing equipment are also needed, especially if you have several heating circuits.

The labour charge varies from a few days to a couple of weeks depending on the design of the heating system proposed. This may be in the range of £1500 to £6000 with plumbing supplies (e.g. copper pipe) being extra.

For your average domestic installation, the costs would be towards the lower end, especially if it’s a new build.

How can I Find out More?

We’re here to help.

If you need help switching, or you would like some more information, then give us a call on 01225 580401, or fill in the contact form on the top right of the page, or here.

A wood pellet boiler is the future of sustainable home heating, but there’s more to them than just that; lets have a further look.

Sustainability

Lets start with the obvious here. Even if you were to forget about the many other advantages of wood pellet boilers, sustainability is one reason you couldn’t forget. Rather than burning a fossil fuel, you’re burning what could effectively be considered wood waste. You remove waste, and create heat/energy at the same time, without impacting the environment.

Low emissions

The approximate life cycle CO2 emissions (including production) of coal is 484 kg/MWh, which is a lot of CO2. With oil and natural gas it’s 350 and 270 kg/MWh respectively. When you compare those to the emissions of wood pellet boilers though, you see a very different story. It’s around about 25 kg/MWh, which is a huge difference, so you’re not only using a sustainable fuel source, but you’re saving the environment at the same time.

Receive an income under the Renewable Heating Incentive (RHI)

There is already a RHI for commercial buildings, but next year, there’s going to be one for domestic installations too, and this is a pretty big deal. Here’s why.

Firstly, if you live off the mains gas grid, you’re already entitled to a £950 grant to help towards the cost of a biomass boiler.

Then, from about mid 2013 though, the Government will start to pay homeowners for the green heat they generate from biomass boilers. Full details about the levels of payment are due to be announced by the Energy Saving Trust later this year, but it’s certainly an added incentive for anyone looking to make the switch.

Low running costs

The price of wood is much lower than the price of oil, and what’s more, it can be sourced locally. It’s not travelled, hundreds, if not thousands of miles to reach you. The price of wood is also much less likely to fluctuate as wildly as gas and oil does, as the world market has basically no effect.

No need to be connect to the grid

So as I mentioned, there’s currently a grant for those who choose biomass boilers when living off the grid, and that’s one of the great things about it, you don’t actually need to be connect to the grid. Not having access to gas mains is no longer a problem with a wood pellet boiler, in fact, it’s an advantage.

Automatic ignition and self-cleaning

When you think about wood pellet boilers, you might think that you have to sacrifice more of your time cleaning, and igniting the boilers, which doesn’t really sound like fun. Most boilers these days contain an automatic ignition, and are self-cleaning, which takes a lot of the hard work out for you. You might need to give is a brush every couple of weeks, but that’s nothing compared to the advantages.

Commercial and domestic installations

Wood pellet solutions aren’t just for domestic installations, as you’ve probably gathered by now. They can be scaled up to suit any of your commercial or domestic needs. And green business have become a selling point in recent years. People like to see that big businesses aren’t damaging the environment, so by sourcing your energy sustainably, you can do your bit, and gain positive recognition.

Smaller and easier than logs or wood chips

Much less bulky in size, and they burn cleaner than logs or wood chips. This makes them ideal for home solutions where you don’t want to dedicate so much room to your boiler. Storage is also much smaller, and can be hidden away, unlike wooden logs, which tend to take up a lot of room. And unlike logs, you can use an automatic hopper to add the fuel to your boiler, saving you time and work.

Long life

The boilers that we sell are fantastically well made, and so long as your follow the manufacturers servicing schedule, and maintenance guidelines, you’ll be sure to have a boiler that’s going to last. Have a look at our boilers here.

It’s easy to switch

From our sales team, to our team of approved installers, we have anything you need to get started with your wood pellet boiler. Before long, you could be taking advantage of the RHI, lowering your running costs, becoming more sustainable, and helping the environment. If this sounds like something you might be interested in, then click here and fill in a contact form; we’ll get right back to you. Alternatively, you could call 01225 580401. We cover the whole of the UK.

As part of our service we assess requirements and properties to help you choose the right system or boiler for your heating and lifestyle choices. This post is all about Wood Pellet Boiler Installations.

For this we asked Tom Jacques, an architect and RIBA Client Adviser based in the South West for some comments.

Tom responded with 3 articles the third of which is below.

Part 3 General rules about wood pellet heating

Rule 1 – Most estimates on websites are unreliable

As the complexity of the system selected increases, the parts and the labour go up in price significantly. However the maintenance levels go down and the efficiency of the system goes up.

Expensive parts do include the pellet boiler which ranges in price from £3000 to £17,000 but also:

The flue – this can cost between £750 and £2000

Accumulation or climate control – between £850 and £2000

Pellet Store – You can use the integrated hopper that will last you a few days at peak load. Otherwise there are several options. A steel hopper may cost between £2000-£3000, as may a flexible liner in steel frame.

Pump sets and other plumbing equipment are also needed, especially if you have several heating circuits.

The labour charge varies from a few days to a couple of weeks depending on the design of the heating system proposed. This may be in the range of £1500 to £6000 with plumbing supplies (e.g. copper pipe) being extra.

Rule 2 – Everyone is an expert

We accept that the market is relatively new. Whilst most MCS accredited installers are very good and knowledgeable we have found that people’s knowledge varies. This includes consultants, other technologies, advice centres, builders, architects etc

If you have a budget and know what you want, do invite several companies to quote. Any risks that there may be can be identified and ironed out.

Rule 3 – Do the sums

We often suggest biomass as we think it has great potential as an alternative to oil and Lpg, particularly where heat loads are higher. Occasionally other solutions, including ground source heat pumps, air source heat pumps, solar thermal, and electrical generation and output devices may be preferable, or used in combination, and should also be considered.

All renewable technologies have the benefit of being able to have MCS accreditation. As such when your house is assessed, they should tell you how much heat you can get from their system, how much it will cost to install and run. It is then a fairly simple process of firstly doing the sums and then secondly having a feel about which technology you like best and works in your situation.

Key considerations for “doing the sums” are to:

Understand your own heating needs. What heat did you use last year? For instance if you used 2000 litres of oil you burnt about 20,000 kWhs of energy. At 60p a litre this is £1200. This costs 6p per kWh

Get a price for the equipment and installation along with the output or performance, probably in kWs.

Understand how the equipment works at its best and its worst so that you can get an idea of operating costs. ie. how many tonnes of pellets do I need to burn? Pellets often release 4800 kWhs per tonne. In the above example this would be approximately 4.2 Tonnes of pellets. This gives a fuel bill of about £800 and a saving of £400. This costs 4p per kWh

For Heat pumps understand the co-efficient of performance (COP). For instance a heat pump will perform differently based on:

The type e.g. Air Source heat pump or Ground source heat pump,

The job it is being asked to do e.g heating water to 60 degrees C

The temperature of the air or ground where the heat exchange is taking place, and maintaining optimum performance.

Each kWh of “free energy” needs electricity to power the heat pump. If the COP is 2:1 then you get 2 units of heat for 1 unit of electricity.

A recent study of heat pumps in 2010 – “Getting-warmer-a-field-trial-of-heat-pumps” by the Energy Savings Trust suggested that the COP or Coefficient of Performance for heat pumps varied between 1.2 and 3.6 with a mid range of 2.2 for ASHP and 2.3-2.5 for GSHP. If electricity is 15p a kWh (then you would be paying between 12.5p and 4.2p per kWh with the majority of outcomes being between 6 and 6.8p per kWh ie a total bill of about £1200. Clearly if you had a PV installation with spare capacity or a “special” rate then you can reduce this cost.

Similarly, if the electricity is obtained through the mains, system losses will be taken into account in any calculation of carbon consumption and overall efficiency.

With the Renewable Heat Incentive, the rates for non domestic RHI have been published and this gives you an idea of the possible rates for domestic RHI in the future. Biomass is 7.9p a kWh, Solar 8.5p, and GSHP 4.5p. For 20,000 kWh’s of heat biomass wood pellets would gain nearly £1600 per annum for 20 years.

Rule 4 – The price of fuel will go up in price

Unfortunately we are in a volatile period for prices. Electricity, gas and oil are likely to keep going up in price. No one really knows by how much. There is greater demand for a diminishing world supply, resulting in a shortfall in the amount of energy to go around. In general oil and gas go up in price when you need it most.

Wood pellets are being made all over the country and there are more pellet suppliers than there are electricity providers (or gas and oil producers). This means it is a more competitive market which is likely to remain price sensitive for some time to come. Clearly there is a potential limit for how many wood pellets can be produced. The main constraint is the supply of raw material either sawdust or recycled wood. Many providers have fixed their prices to give confidence in the industry and it is very unlikely that you will get a monopoly in the same way as other forms of fuel. Still, it is likely to make more sense to order when demand is lowest.

For a good idea of relatively up to date price comparisons do click here

Rule 5 – Simple is best

With all the above points there is a tendency to get confused or wedded to a particular solution which may prove inappropriate, or to get consumed by too much detail at an early stage. Do take advantage of your home as it is. If you are combining alterations with an extension, consider how best use can be made of each element, and what can be best located where. Do ensure that you minimise heat loss as this is usually the most cost effective intervention which can be made. For systems installed do consider carefully how you will use and maintain the buildings and systems installed, for example the trade off between filling a hopper once or twice a week against once or twice a year (and the increase in costs that will result). Do use existing chimneys where possible as this will decrease your costs.

If biomass forms part of your solution, some of the choices you will make will be substantial and make a difference to the costs and effectiveness of the system. Other choices will be a bit like choosing a car. Once you have narrowed down the options by essential criteria, the remaining options will largely do the same job, but preferences can lead to significant price differences even within a model.

Installation costs are normally quite similar between companies for the same job, (it is worth getting alternative quotations to verify this), but the more complex the system, the higher the installation costs.

Tom Jacques

Tom Jacques is an architect and RIBA Client Adviser based in the South West.

Alongside interpreting,defining and meeting clients spatial and aesthetic requirements, Tom prioritises environmental design alongside an understanding of building physics, the use of appropriate technology, and the performance of buildings and their systems in use.

He embraces different approaches in different circumstances, and works where possible with specialists in their fields. Many of his projects involve work with listed buildings and in sensitive settings, and where planning and listed buildings consent is required.

He is not a specialist in any particular product or technology, nor a building services engineer, but is able to offer advice and assistance on projects where required.

If you wish to contact Tom, please contact us and we will pass your comments on to him.